using an Array entry to refer to another Array

[pob327]

G'day all, I have an Array composed of various numbers. I want to select one of those entries then add or subtract from that entry and use the result to refer to a second Array.
The problem I am having is that javascript keeps assuming I am dealing with string values. How can I get round this ?

specifically if starSquare is 45 (see code below) and startSquaresList[startSquare] is 77, I want startSquaresList[startSquare] + 1 to be 78, but it keeps coming out 771 !

Here is the code I have:

- startSquare is a number generated by Math function.

document.getElementById("coords").value = "startSquare =" + startSquare + " - " + startSquaresList[startSquare] + " - " + startSquaresList[startSquare] + 1;

 

[pob327]

Ok, as is so often the case, I was just being a bit thick about this.
For anyone who was as thick as me, you have to do the addition/subtraction then write it to "coords".

var surroundSquares = Number(startSquaresList[startSquare]) + 1;
document.getElementById("coords").value = "startSquare =" + startSquare + " - " + startSquaresList[startSquare] + " - " + surroundSquares;

 

[trollacious]

You could do it inline, too, forcing the order of operation using parentheses and parseInt():

document.getElementById("coords").value = "startSquare =" + startSquare + " - " + startSquaresList[startSquare] + " - " + (parseInt(startSquaresList[startSquare], 10) + 1);

Lee